Abstract: Musical information is analyzed in terms of pitch and/or amplitude to provide an output which is useful in controlling musical synthesizers but may have other applications also. By controlling music synthesizers, synthesized sounds may be played in synchronism with source music. Detection of musical gestures occurs in the present improved method, a musical gesture being the onset or cessation of individual notes comprising a musical performance or the like. The method comprises measuring at selected points in time the pitch and/or amplitude of the musical signal, calculating the change in pitch and amplitude at intervals, calculating the change of said changes in pitch and/or amplitude at intervals, comparing these change of changes to threshold values, and providing the change of changes in pitch and/or amplitude exceeds the threshold, generating a signal signifying the onset of the musical gesture.